July 23, 2014

Strange things: white holes, electric bacteria and what tree rings sound like when played on a turntable

A few of the strangest things

White holes. Black holes explode when they die and become white holes at the end of their life spewing out all the matter it sucked in as a black hole

A new theory suggests that black holes might die by transforming into a 'white hole,'which theoretically behave in the exact opposite manner as a black hole - rather than sucking all matter in, a 'white hole' spews it out. The theory, as first reported by Nature.com, is based on the speculative quantum theory of gravity. Scientists believe it may help determine the great debate over black holes about whether they destroy the things they consume. According to the theory, a 'white hole' would explosively expel all the material consumed by a black hole.
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It's long been suspected that gigantic black holes lurking in the heart of galaxies rotate faster and grow larger as they feast on gas, dust, stars and matter. But there hasn't been a reliable measurement of the spin rate of a black hole until last year. While black holes are difficult to detect, the region around them gives off telltale X-rays.

Using NASA's newly launched NuStar telescope and the European Space Agency's workhorse XMM-Newton, an international team observed high-energy X-rays released by a supermassive black hole in the middle of a nearby galaxy.
They calculated its spin at close to the speed of light — 670 million mph.
It was the first 'unambiguous measurement of the spin rate' of a supermassive black hole, University of Maryland astronomer Christopher Reynolds, who had no role in the research, wrote in an accompanying editorial.

Black holes: According to a new theory, a 'white hole' would explosively expel all the material consumed by a black hole

While a black hole sucks matter in, a white hole expels matter at an explosive rate

Unlike any other life on Earth, these extraordinary bacteria use energy in its purest form – they eat and breathe electrons – and they are everywhere.

STICK an electrode in the ground, pump electrons down it, and they will come: living cells that eat electricity. We have known bacteria to survive on a variety of energy sources, but none as weird as this. Think of Frankenstein's monster, brought to life by galvanic energy, except these "electric bacteria" are very real and are popping up all over the place.

Unlike any other living thing on Earth, electric bacteria use energy in its purest form – naked electricity in the shape of electrons harvested from rocks and metals. We already knew about two types, Shewanella and Geobacter. Now, biologists are showing that they can entice many more out of rocks and marine mud by tempting them with a bit of electrical juice. Experiments growing bacteria on battery electrodes demonstrate that these novel, mind-boggling forms of life are essentially eating and excreting electricity.

Geobacter

The discovery of electric bacteria shows that some very basic forms of life can do away with sugary middlemen and handle the energy in its purest form – electrons, harvested from the surface of minerals. "It is truly foreign, you know," says Nealson. "In a sense, alien."